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Kool Mods

Vintage 'GMT' - Custom Mod Watch

Vintage 'GMT' - Custom Mod Watch

Regular price $515.00 AUD
Regular price Sale price $515.00 AUD
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Bezel Colour

View our Custom Seiko Mod Vintage 'GMT' Watch

Inspired by the classic GMT master multi time-zone watches, our Custom GMT Mod Watch pays homage to this legendary design while adding modern elements for a contemporary twist.

*Note - Please add in special order instructions if you would like a cyclops or not.


  • Flat Sapphire / Domed Acrylic


  • Case Material: 316L Stainless Steel
  • Caseback: Stainless Steel Screw-down caseback
  • Case Size: 40MM
  • Case Thickness: 13.5MM (Flat Sapphire) 16MM (Domed Acrylic)
  • Lug to Lug: 47.5MM 
  • Bezel Material: Aluminum 
  • Dial Colour: Black 


  • Bracelet / Strap Material: 316L Stainless Steel
  • Lug Width: 20MM


  • Caliber: NH34A 
  • Movement Type: Automatic 
  • Water Resistance: 10ATM (Pressure Tested)
  • Power Reserve: 41 Hour 

Handling Time

As each watch is custom built to order, please expect a 2 to 4 week build time. We try to turn around under the handling time but occasionally delays can occur.

Water Resistance

A watch that is water-resistant to 5ATM (50 meters or 165 feet) can handle more than just occasional splashes of water. However, to ensure your watch remains in optimal condition and retains its water resistance, proper care is essential. Here’s a comprehensive care guide to help you maintain your 5ATM water-resistant watch.

Understanding 5ATM Water Resistance

Before diving into the care instructions, it’s important to understand what 5ATM water resistance means.

  • 5ATM indicates that the watch can withstand water pressure up to 50 meters deep.
  • This rating is suitable for light water activities such as swimming in shallow water.
  • It is not suitable for diving, snorkelling, or any high-pressure water activities.

Daily Care and Maintenance

  1. Rinse After Exposure to Salt Water or Chlorine: After swimming in the ocean or a chlorinated pool, rinse your watch with fresh water. Salt and chlorine can cause corrosion and damage the watch seals over time.
  2. Avoid Hot Water: Do not wear your watch in hot showers, saunas, or hot tubs. The heat can cause the seals to expand and contract, compromising the water resistance.
  3. Check the Crown and Pushers: Always ensure the crown (the knob used to set the time) and any pushers (buttons) are fully pushed in and/or screwed down. Water can seep into the watch if these parts are not secure.

Important Links

Please ensure you are familiar with our policies and contact details:


We're happy to answer any questions. Click our Contact Page for contact details.

Customer Reviews

Based on 3 reviews
Shaun O'Hagan

Highly recommended - will be purchasing from Kool Mods again in the near future!

Will D
Seiko GMT Coke

Words can’t describe how happy I am with the end product. I contacted KoolMods around 3-4 weeks ago and spoke with Riley. I told him I was interested in a custom watch based off the 2004 Rolex GMT “Coke”. Riley was very helpful throughout the whole process by sending me photos of all the different materials , looms, bezels, glass type and bracelet type to ensure what I was asking for was 100% correct. I revived my watch very quickly and am blown away by the quality I have received. 10/10 would recommend for anyone interested in designing their own Seiko Custom watch.

Seiko GMT Neo Vintage Dial Black Bezel

My first impressions are very positive, this is a vintage style that I have loved for a long time. I like the slight Sun ray on the dial to make it unique, the combination of clean maxi stle hour markers combines the modern and vintage gmt style very well. I also like the sizing a lot, I tend to lean to 40mm or less so this hits the spot.

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